It is frequently desirable to scan hardcopy photographs to produce corresponding digital images. A wide variety of digital scanners have been developed for this purpose and are widely available in many different forms, including scanner modules included in all-in-one printers.
Scanners are frequently used to scan composite images that include two or more individual images such as a photographic album page, a scrapbook page, a photo collage or a page of a printed publication. Users often desire to segment the scanned composite image into its individual images.
Many scanner user interfaces allow users to indicate a rectangular area of a composite image that they would like to scan. However, a disadvantage to this approach is that it requires users to manually perform multiple scan operations if they want to scan all of the individual images.
Alternately, image editing applications such as Adobe Photoshop can be used to edit the composite image, manually selecting each of the individual images and saving them as individual image files. However, this requires special software that many users do not own. Additionally, it can be a very time-consuming process that is frustrating to the user.
Recently some scanners have started to include automatic photo segmentation algorithms that attempt to automatically segment a composite image into its component individual images. For example, many Kodak inkjet printers, such as the KODAK ESP 5250 All-in-One Printer, include this capability. These image segmentation algorithms typically assume that the composite image is composed of a set of individual images on a white or black background. They generally identify the borders of the individual work by identifying rectangles that contain content that does not match the expected background region. Such algorithms are typically not robust for composite images having backgrounds with other colors and textures. They also typically need to make assumptions about the number and size of the individual images that make up the composite image.
U.S. Pat. No. 7,020,352 to O'Callaghan et al., entitled “Photo extraction techniques,” discloses a photo extraction technique that includes scanning film within a holder. The scanned image is analyzed to detect edge segments for an image-holding area corresponding to the borders holder. The image-holding area is then extracted from the scanned image.
U.S. Patent Application Publication 2006/0114518 to King, entitled “Photographic data conversion method and apparatus,” discloses a method to convert various photographs from a photographic album to digital form. In some embodiments, an edge-detection algorithm is used to detect the borders of the individual photographs in a scanned album page.
U.S. Patent Application Publication 2007/0116362 to Tiede, entitled “Method and device for the structural analysis of a document,” discloses a method in which a document is broken down into elementary structural units. Individual objects are produced based on the elementary structural units.
There remains a need for a robust and efficient method to segment a composite image into a plurality of individual images.